Don't let fear or insecurity stop you from trying new things. Believe in yourself. Do what you love. And most importantly, be kind to others, even if you don't like them.
You have to look in the mirror and see that what you're wearing looks good on the body you have now. Wearing a larger size is just... wearing a larger size.
Your self-esteem won't come from body parts. You need to step away from the mirror every once in a while, and look for another reflection, like the one in the eyes of the people who love you and admire you.
Clothes allow you to see yourself in a different light. They can transform you instantly and have a very real, visceral impact. Clothes become symbolic of who we are.